Those surveyed are divided on whether the likely Republican nominee is trying to hide anything. While 42% predict the release of additional returns would not reveal anything politically harmful, 44% believe it would include damaging information — including 15% who say they believe the revelations would be so serious that they would “show he is unfit to be president.”

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In the poll, those surveyed:

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• Agree by a substantial margin of 17 percentage points that Romney in particular should release more than two years of returns. By 54%-37%, they say Romney should release tax returns from additional years. Those calling for more disclosure include 75% of Democrats, 53% of independents and 30% of Republicans.

If nearly a third of Republicans and over half of independents want the tax returns released, it’s hard to see this as a solely partisan matter, although, of course, the percentage of Democrats who want them released is by far the highest.